ZOOLOGISCHE MEDEDELINGEN

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1 MINISTERIE VAN ONDERWIJS, KUNSTEN EN WETENSCHAPPEN ZOOLOGISCHE MEDEDELINGEN U1TGEGEVEN DOOR HET RIJKSMUSEUM VAN NATUURLIJKE HISTORIE TE LEIDEN DEEL XXXI, No Juni 1952 NOTES ON THE THYSANURA (INSECTA, APTERYGOTA) OF THE CANARY ISLANDS by PETR WYGODZINSKY Institute de Medicina Regional, Tucuman, Argentina (with 16 text-figures) (34th Contribution to the knowledge of the Fauna of the Canary Islands, edited by Dr. D. L. Uyttenboogaart, and continued by Dr. C. O. van Regteren Altena )) 1 The present paper constitutes a report on the Machilidae and Lepismatidae collected by Dr. C. O. van Regteren Altena in the Canary Islands in the spring of We are much obliged to Dr. van Regteren Altena for allowing us to study these interesting specimens. The first notice on Thysanura from the Canary Islands seems to be the mentioning of Machilis maritima by Lucas ( ). Unfortunately it is quite impossible nowadays to identify that species as understood by Lucas. Ridley (1881) mentions three species from the Canary Islands, viz., Lepisma saccharina L., from Tenerife and Gran Canaria; Lepisma mauritanica Lucas, from Las Palmas (Gran Canaria) and Lepisma eatonii Ridley, from Tenerife. L. saccharina has apparently not been found again on the Islands; anyhow we do not see any reason to doubt its presence there. Lepisma mauritanica, actually included in the genus Ctenolepisma, is a species that is rare as well as very difficult to identify; Ridley's specimens were most probably nothing else but dark Ctenolepisma lineata, a species common in the Islands. Finally Lepisma eatonii, whose correct name should be Ctenolepisma lineata eatonii, is nothing more than a colour form of Ctenolepisma lineata, which may not deserve even subspecific rank. 1) Contribution No. 33 has been published in Tijdschr. v. Entom., vol. 92 (for 1949), i960, pp

2 226 PETR WYGODZINSKY Escherich (1905) also mentions Ctenolepisma lineata eatonii from Tenerife. Silvestri (1940) gives the first record for Lepisma myrmecobia Silvestri from the Islands (Gran Canaria and Tenerife). Wygodzinsky (1941) described Dilta insulicola from Tenerife. In the present paper an additional species of Dilta, Dilta altenai sp. n. is described from Tenerife, and several of the formerly known species of Thysanura are mentioned. The total of accepted species of Thysanura from the Canary Islands is therefore as follows: Family Machilidae Dilta insulicola Wygodzinsky, 1941 Dilta altenai sp. n. Family Lepismatidae Ctenolepisma lineata (Fabricius, 1775) Lepisma myrmecobia Silvestri, Lepisma saccharina L., 1758 Our knowledge of the Thysanura of the Atlantic Islands is still very incomplete; thus we think it premature to make comparisons between their respective faunae. From what we know to date, it might be said that the Thysanura of the Canary Islands, the Azores, and Madeira have exclusively palaearctic affinities; as to the Cape Verde Islands, we find mixed palaearctic and ethiopic elements. It is almost certain that the two species of Dilta found in the Canary Islands are endemic; but as the genus is exclusively palaearctic, the general picture is not changed. Dilta insulicola Wygodzinsky, 1941 This species is based upon the description of a not too well preserved male. We have now seen three females, which allow us to complete the diagnosis of the species. The following description contains only those characters peculiar to the female, or those of general interest which it was not possible to examine in the male. Female. Maximum length 15 mm. Antennae longer than body (preserved portion 17 mm), not distincly thickened near base. Scapus very elongate (figs. 1, 2), in lateral aspect of head distinctly more than twice as long as eye. Distal articles divided into eight sub joints.

3 THE THYSANURA OF THE CANARY ISLANDS 227 Maxillary palp long and stout, the shape and relative length of its articles as in fig. 3. Labial palp as in fig. 4, its apical joint slightly triangularly widened. Legs long and stout, ventral surface of arcticles with long and numerous bristles. Coxal appendages on legs II and III. Relation length of stylet: length of coxite, on segments II-VII = 0.45, VIII = 0.7, IX = 0.6. Ovipositor simple, surpassing stylets of segment IX Dilta insulicola Wygodzinsky, female. Fig. 1, head, lateral view; fig. 2, scapus; fig. 3, maxillary palp; fig. 4, labial palp. Wygodzinsky del. by the whole length of the latter. Chaetotaxy of gonapophyses as typical for the genus. Anterior gonapophyses with joints. Material examined: Tenerife, Barranco west of Icod el Alto, 25-III-1947 (1 female, allotype, Mus. Leiden; 1 female, author's collection); Tenerife, Barranco Andura or Andola, south of Realejo Alto, 17-III-1947 (1 female, Mus. Leiden); Tenerife, Barranco Ruiz, west of Realejo Bajo, 1-IV-1947 (1 female, Mus. Leiden). As mentioned in the original description of this species, D. insulicola differs from the remainder of the species of the genus by its large size, the very stout and elongate palpi and legs, and, as we may now add, by the antennae, whose length surpasses that of the body, and which are not notice-

4 228 PETR WYGODZINSKY ably thickened at their base. We do not, however, consider these characters sufficient for the erection of a new superspecific unit, e.g., a subgenus or genus, at any rate until we learn of the existence of additional species with identical characters. Dilta altenai sp. n. Maximum length of male 8, of female 10 mm. Colour pattern unknown. Eyes black; line of contact: length = 0.5. Length: width = 0.4. Ocelli subquadrate, dark coloured. Antennae shorter than body, very stout, as usual in the genus; apical joints composed of 6-9 subjoints. Maxillary palp of male with moderately long ciliate hairs on the ventral surface of all joints, somewhat more numerous at apex of last joint. Shape and relative length of joints as in fig. 13. Maxillary palp of female simple, shape and relative length of joints as in fig. 14. Second joint of labial palp of male with a rounded salience subbasally on anterior surface; this salience bears a number of short conical hyaline spines which come into contact with the spine tuft of the clypeus (see below); near the base of this salience there is a longitudinal fascia of numerous tiny delicate bristles. Posterior surface of second joint with a fascia of numerous long and stout bristles which also exist on the posterior surface of basal joint. Centre of posterior surface of second joint with a slightly dorsally situated group of subglobular papillae. Third joint of labial palp of male strongly triangularly widened, its posterior surface with numerous long bristles like those on second joint; sensory spines of anterior surface numerous. Labial palp of female as in fig. 12. Clypeus of male with lateral tufts of slender, slightly pigmented spines (figs. 7, 8); clypeus of female simple. Apical region of inner surface of fore femur of male and the whole of the inner surface of fore tibia with numerous delicate sensory bristles. Ventral surface of fore trochanter and femur of male with numerous spinelike bristles, very short on trochanter and base of femur (fig. 15), longer towards apex of the latter (fig. 16). Mid and hind legs of male without special characters. Legs of female without special characters, the setae on ventral surface of fore legs slender and not numerous. Hairs on urosternites in moderate number. Relation length of stylet: length of coxite, in the male, on segments II-VII = 0.4, VIII = 0.6, IX = 0.6; in the female, on segments II-VII = 0.4, VIII = 0.8, IX =

5 THE THYSANURA OF THE CANARY ISLANDS 229 O.6. Ovipositor simple, slightly surpassing the apex of terminal setae of stylet IX. Gonapophyses VIII with joints, their chaetotaxy as usual Dilta altenai sp. n. Fig. 5, head of female, lateral aspect; fig. 6, eye and ocellus, frontal view; fig. 7, clypeus and labrum of male; fig. 8, setae of tufts of clypeus of male, high magnification; fig. 9, scapus of female; fig. 10, labial palp of male, with its bristles; fig. 12, labial palp of female; fig. 13, maxillary palp of male, with its ciliate hairs; fig. 14 maxillary palp of female; fig. 15, spine-like setae on ventral surface of fore trochanter of male; fig. 16, idem, on apex of fore femur. Wygodzinsky del. in the genus. Anterior parameres of male with 5-6 joints, posterior ones with about 8. Penis reaching to tip of posterior parameres.

6 230 PETR WYGODZINSKY Material examined: Tenerife, Barranco Andura or Andola, south of Realejo Alto, 17-III-1947 (1 male, holotype, 1 female, allotype, 2 males and 3 females, paratypes, Mus. Leiden; 2 males and 1 female, paratypes, author's collection); Tenerife, Agua Garcia, above Tacoronto, =h 800 m, 15-III (2 females, paratypes, Mus. Leiden); Tenerife, beach east of La Paz, near Puerto Orotava, 19-III-1947 (6 females, paratypes, Mus. Leiden); Tenerife, Agua Mansa-Portillo, m, 2-V-1947 (1 female, Mus. Leiden); Tenerife, Las Mercedes, zh 650 m, 22-III-1947 (1 female, Mus. Leiden). The new species which we have great pleasure in dedicating to its collector, differs completely in the male from all formerly described Dilta; the peculiar armature of the clypeus and the shape and setae of the labial palpus are very characteristic. There are very few morphological characters for the determination of most of the females of Dilta, the chief feature of specific value being probably the colour pattern, generally not perceptible in preserved specimens. The female of altenai differs from the other Canarian species, insulicola Wygodzinsky, by the characters mentioned in our key; as to the remainder of the genus, altenai can only be separated from the females of hibernica (Carpenter) and suecica Agrell, whose anterior gonapophyses are composed of a much smaller number of joints than in the present species; as to the remainder of the species of the genus, no good differential characters are available. The following key for the determination of the species of Dilta described to date, must only be applied to mature specimens; especially since the secondary sexual characters of the male make their appearance in that stage only. If only females are known from a certain locality, it will be advisable to list them as Dilta spec, unless males be found later or more becomes known on the colour pattern or other characters that might lead to a specific identification in this sex. Key for the males of Dilta 1. Second joint of labial palp simple, viz., without processes or specialized bristles 2 Second joint of labial palp with peculiar processes and/or specialized bristles 3 2. Very large, stout species (12 mm or more); antennae longer than body; scapus twice as long as eye, in lateral aspect (fig. 1); fore tibia with an extensive field of short sensory bristles; palpi strong and elongate, last joint of labial palp strongly triangularly widened insulicola Wygodzinsky Smaller species (less than 12 mm); antennae shorter than body; scapus not much longer than eye, in lateral aspect (as in fig. 5); fore tibia without sensory bristles; palpi short, last joint of labial palp clavate lundbladi Agrell 3. Base of second joint of labial palp with a large rounded process on which there

7 THE THYSANURA OF THE CANARY ISLANDS 231 are inserted numerous conical sensory spines (fig. n) ; clypeus with i + I groups of sensory spines (figs. 7, 8) altenai sp. n. Base of second joint of labial palp without such a process; clypeus without groups of sensory spines 4 4. Centre of anterior border of second joint of labial palp with a group of about 12 stout sensory spines 5 No such group on anterior border of second joint of labial palpus Lateral surface of second joint of labial palp with a longitudinal fascia of short spines, in addition to a similar fascia on posterior surface littoralis (Womersley) Lateral surface of second joint of labial palp without the mentioned fascia italica (Grassi) 6. Anterior surface of second joint of labial palp without spiniform setae. 7 Anterior surface of second joint of labial palp with an irregular fascia of long and strong spiniform setae hibernica (Carpenter) 7. Posterior border of second joint of labial palp with delicate and relatively elongate spiniform setae; ventral surface of trochanter, femur, and tibia of fore legs with very elongate spiniform setae; internal surface of anterior femur and tibia with a large number of delicate sensory hairs.... thornleyi (Womersley) Posterior border of second joint of labial palpus with short and stout spines; ventral surface of trochanter, femur, and tibia of fore legs with very short spiniform setae; only the internal surface of fore tibia with numerous sensory hairs saxicola (Womersley) Key for the females of Dilta 1. Large and stout species (15 mm); antennae longer than body; scapus twice as long as eye, in lateral aspect (fig. 1); ovipositor surpassing apex of stylets IX by the whole length of the latter; gonapophyses with joints insulicola Wygodzinsky Smaller and more delicate species; antennae shorter than body; scapus not much longer than eye, in lateral aspect (as in fig. 5); ovipositor not or only slightly surpassing apex of stylets IX; gonapophyses with smaller number of joints Anterior gonapophyses with segments 3 Anterior gonapophyses with not less than 47 joints italica (Grassi); littoralis (Womersley); lundbladi Agrell; saxicola (Womersley); thornleyi (Womersley) and altenai sp. n. 3. Anterior gonapophyses with joints.... hibernica (Carpenter) Anterior gonapophyses with joints suecica Agrell Lepisma myrmecobia Silvestri, 1908 Material examined: Tenerife, Barranco near Tacoronte, 20-III-1947 (1 male, Mus. Leiden). Ctenolepisma lineata (Fabricius, 1775) The specimens seen are very variable in the intensity of their pigmentation, those from higher altitudes being much darker than those captured at or near sea-level. We are convinced that the var. eatonii Ridley, 1881, does not deserve taxonomic rank, and thus consider it as a simple synonym of lineata.

8 232 PETR WYGODZINSKY Material examined: Tenerife, Las Canadas and Pico del Teide, m, 28/29-III-1947 (5 females, Mus. Leiden) ; Barranco west of Realejo, at the coast, 2-IV-1947 (1 male, Mus. Leiden); Tenerife, Icod de los Vinos, 5-IV-1947 (1 male, 1 female, 1 small specimen, Mus. Leiden); Tenerife, Barranco Martianez, east of Puerto Orotava, 27-III-1947 (1 male, Mus. Leiden); Tenerife, between Guimar and Socorro, 12-IV-1947 (1 male, 2 females, Mus. Leiden) ; Tenerife, Los Cristianos, 16-IV-1947 (1 male, 2 females, Mus. Leiden). RESUMEN Se examinan los tisanuros coleccionados por el Dr. C. O. van Regteren Altena en las Islas Canarias, en la primavera de Hasto la fecha se conocen de las Islas Canarias los lepismatidos Ctenolepisma lineata, Lepisma myrmecobia and Lepisma saccharina, y los maquilidos Dilta insulicola y Dilta altenai, siendo esta ultima especie descripta como nueva. Aunque nuestros conocimientos incompletos no permiten conclusiones zoogeograficas muy amplias, podemos decir que la fauna de tisanuros de estas islas tiene afinidades puramente palearcticas. BIBLIOGRAPHY ESCHERICH, K., Das System der Lepismatiden. Zoologica (Stuttgart), vol. 43, 164 pp., 67 figs., 4 pis. LUCAS, H., Thysanoures. In: P. B. Webb & S. Berthelot, Histoire Naturelle des lies Canaries, vol. 2 (2), pp RIDLEY, H. N., Notes on Thysanura collected in the Canaries and Madeira. Ent. Mon. Mag., vol. 18, p SILVESTRI, F., Primo contributo alia conoscenza dei Tisanuri del Peru e descrizione di un genere e due especie deir Argentina settentrionale. Boll. R. Lab. Ent. Agr. Portici, vol. 6, pp , 10 figs. WYGODZINSKY, P., Thysanuren aus Nordafrika und von den atlantischen Inseln. Mitt. Schweiz. Ent. Ges., vol. 18 (4-5), pp. 1-24, 9 figs.